1. Field of the Invention
The present invention relates generally to anti-pollution apparatus and methods and, more particularly, to such apparatus and methods which may be added to an internal combustion engine fuel supply system for promoting increased combustion efficiency.
2. Description of the Prior Art
It is a well known fact that internal combustion engines do not operate at 100% efficiency. In fact, operating efficiency of conventional engines, as used in the propulsion of automobiles, trucks and other vehicles, is considerably less than 100% due primarily to heat losses and the incomplete burning of the fuel during the combustion cycle. Incomplete combustion not only reduces efficiency, but results in the generation of unburned hydrocarbons, carbon monoxide, and oxides of nitrogen in the engine exhaust. These and other constituents of internal combustion engine exhaust act either directly or by photochemical reaction with sunlight as air-pollutants. With the rapid increase in the number of automobiles, the presence of such pollutants in the environment has likewise rapidly increased with the result that several laws and regulations have been passed in an effort to reduce pollution and protect the environment.
In an effort to at least partially solve the pollution problem and, at the same time, increase engine efficiency, automotive engineers have tried several different approaches, some involving complete engine redesign and others involving the addition of supplemental systems to conventional engines. While various prior art approaches have proven to be successful in certain limited ways, a complete solution to the problem of automobile pollution and reduced efficiency heretofore has not been achieved.
An early approach to the improvement of internal combustion engine operating efficiency is shown in U.S. Pat. No. 550,776. In this patent, fuel vapors are drawn off by a partial vacuum existing within a chamber from which the vapors are fed directly to the engine carburetor. By supplying the carburetor with fuel vapor, rather than liquid fuel, it was believed that the operating efficiency of the system would be enhanced. Much later, a similar system was disclosed in U.S. Pat. No. 2,298,214 in which fuel, maintained liquid under pressure, is evaporated and cooled in a cooling coil disposed about the combustion cylinder. The cooling coil maintains the cylinder temperature within an acceptable range, and the evaporated fuel is then fed directly to the engine carburetor.
The above patents were based, at least in part, upon the theory that engine operating efficiency would be increased by the development of a fuel vapor for feeding the system carburetor. It has recently been postulated that further efficiency increases could be achieved by heating the fuel vapor before it is fed to the engine. Systems including heat evaporating vapor generators are exemplified by the structures shown in U.S. Pat. No. 3,854,463 and No. 4,003,356.
While the devices shown in the above patents and in other improved systems have caused engine efficiency to exceed levels accepted in the past, incomplete combustion, and resulting exhaust pollution, continues to be a serious problem.